Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 19 of 19 for “"place cells"”.
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Charting the hippocampal cognitive map: Investigating the emergence of grid cell and place cell firing patterns in novel and familiar environments
Hippocampal place cells comprise the main building blocks of the cognitive map which is used to encode our surroundings quickly and rapidly. Prominent theoretical models argue that place cells emerge via a linear summation of different grid cells from the medial entorhinal cortex. However, recent …
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Alternating Sequences of Future and Past Behavior Encoded Within Hippocampal Theta Oscillations
… encode locations in space, and are thus termed "place cells". During active exploration, place cells display "phase precession" relative to the ongoing 4-12 Hz theta rhythm, firing at progressively earlier phases of theta as the rat traverses a cell's place field. Across large populations of …
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Memory processing of novel experiences in the hippocampus
… principle neurons of the hippocampus, known as ‘place cells’, exhibit place-selective activity that is thought to reflect spatial aspects of a memory. In addition, during sleep and rest, ensembles of hippocampal neurons periodically engage in coordinated firing that results in signature patterns …
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Towards a theory for the emergence of grid and place cell codes
… to answer the question: which functions grid and place cells perform that directly lead to their own emergence? To answer such a question, an approach that goes beyond a simple modelling is necessary given the fact that there could be circuit solutions other than grid or place cells that better …
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Organised variations in space and time in the hippocampal representation of location
… in the hippocampal formation, including grid and place cells. The cognitive map also flexibly adjusts previous representations to reflect changes in a familiar environment. Several studies have demonstrated continuous spatial and temporal adjustments in how the cognitive map represents the …
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Place cell physiology in a transgenic mouse model of Alzheimer's disease
… impairments (Selkoe, 2001). Hippocampal place cells are a well understood candidate for the neural basis of one type of memory in rodents; these cells identify the animal's location in an environment and are crucial for spatial memory and navigation. This PhD project aims to clarify the …
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Granular retrosplenial cortex layer 2/3 generates high frequency oscillation events coupled with hippocampal sharp wave-ripples and Str. LM high gamma
… active at specific locations in the environment (place cells) increasing their firing rate, functionally representing these specific locations. These firing rate increases are organized within the local theta oscillations and sequential activation of many place cells creates a map of the …
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Combinatorial analysis of sequential firing patterns across multiple neurons decoding memory of sequential spatial experience in rat hippocampus
… through a sequence of spatial receptive fields ("place fields") of hippocampal CA1 "place cells" in a fixed temporal order. The spiking activity of many such individual cells is recorded before (PRE), during (RUN), and after (POST) this experience. By treating each place field traversed as an …
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Mixed Selectivity via Unsupervised Learning in Neural Networks
… selectivity neurons that resembled hippocampal place cells were emerged from models optimised only for behaviour. To understand these results, as well as to generalise the findings to a wider range of computations, I provided a formal connection between learning robust models and mixed …
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Neural prosthetics for paralysis : algorithms and low-power analog architectures for decoding neural signals
… the development of a model of generalized place cells to explain how networks of neurons adapt the configurations of their receptive fields in response to new stimuli, learn to encode the structure of new parameter spaces, and ultimately retrace trajectories through such spaces in the …
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Replay of memories of extended behavior in the rat hippocampus
… During pauses in exploration, ensembles of place cells in the rat hippocampus re-express firing sequences corresponding to recent spatial experience. Such 'replay' co-occurs with ripple events: short-lasting (~50-120 ms), high frequency (-200 Hz) oscillations that are associated with …
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Investigating the role of the hippocampal formation in episodic and spatial memory
… where the temporal component (when) was replaced with another event specifier: context (on ‘which’ occasion). Disruption of the hippocampal circuitry led to a specific impairment in the integration of all three event components, whereas the associative recognition of any combination of …
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Cell-cell communication in three dimensional microenvironments
… in vivo microenvironment and cultured in vitro, cells lose many environmental cues and that may result in abberant behavior, making it difficult to study cellular processes. In order to mimic native tissue environments, optical tweezer and microfluidic technologies were used to place cells within …
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Error correction in the hippocampal-medial-entorhinal cognitive map
… contains multiple classes of spatially modulated cells, namely place cells, grid cells, border cells, and head direction cells. These cell types are thought to create, maintain, and update the cognitive map of the brain. However, they are also known to accumulate error with distance travelled and …
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A role for hippocampal and midbrain neural processing in context-dependent spatial memory
… It is commonly assumed that hippocampal place cells (i.e., neurons that are activated when the animal occupies a particular location in the environment; the place field), underlie this function. However, it has been difficult to ascertain which aspects of hippocampal place fields are …
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Representation of Whole-body Navigation in the Primary Sensorimotor and Premotor Cortex
… the monkey head. The activities</p><p>of these cells were phenomenologically similar to place cells and head direction</p><p>(HD) cells found in rat hippocampus and entorhinal cortices. I observed 44.6%</p><p>and 33.3% of neurons encoding room position in the two monkeys, respectively,</p><p>and …
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Characterising hippocampal replay in the APP<sup>NL-G-F</sup> mouse model of Alzheimer’s disease
… knock-in rodent model of Alzheimer’s disease. Place cells were recorded from the CA1 region of the hippocampus as mice performed a radial-arm maze task, and during subsequent sleep. The task was designed to separably identify errors in reference and working memory. APP<sup>NL-G-F</sup> mice …
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Inhibition, Synapses, and Spike-Timing: Identification and disruption of pyramidal cell-interneuron interactions in SPW-Rs
… CA1, interactions between excitatory pyramidal cells and inhibitory interneurons shape ensemble activity which encodes sequential experience. An extremely diverse set of inhibitory interneurons, with variation in gene expression, synaptic targeting, state-dependent activity, and connectivity, …
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Tracking The Flow of Information Through The Hippocampal Formation In The Rat
… gyrus, the granule cell, has spatially selective place fields; however, the behavioral correlates of another excitatory cell, the mossy cell of the dentate polymorphic layer, are unknown. This report shows that putative mossy cells have spatially selective firing that consists of multiple fields …